1. Field of the Invention
The invention herein pertains to a steam iron and, more particularly, to a novel feed water valve structure between the water tank and the soleplate steam generator to self clean itself of deposits in the water so that tap water in any reasonable locality may be used.
2. Description of the Prior Art
In steam irons a water tank is used above the soleplate and a water valve structure provides controlled water drippage into the steam generator where it is evaporated and directed out soleplate ports to steam the article. Additionally, the water tank may also supply a spray attachment at the front of the iron. Generally, the user is advised to use distilled water because of the fineness of various water passages and orifices which tend to clog due to mineral deposits from the water, which varies locally. Distilled water works well on steam irons since deposits are not plated out of the water onto the metal parts. In hard water localities, the tap water contains minerals which produce loose flakes and deposits that plate out easily onto hot iron components. These deposits varying in various areas of the country generally consist of lime or calcium carbonate as well as other chemicals in solution or in a colloidal suspension. Self-cleaning irons have appeared such as shown in U.S. Pat. No. 3,747,241 of common assignment, where the tank water is suddenly dumped onto the hot soleplate to purge and scrub out the iron prying out the loose deposits and other debris. Other designs blow an extra charge of high pressure steam through the soleplate ports cleaning them. Part of the new self-cleaning concept of applicant's assignee includes cleaning the valve structure per se by a constant scraping action to remove valve deposits which are then carried out of the iron by the self-cleaning action of the U.S. Pat. No. 3,747,241. The two together, purging the tank and passages plus the valve structure cleaning, have provided a self-cleaning iron with much longer life than previously obtainable. The scraping action concept of the metering rod and orifice of the valve structure is disclosed and claimed in U.S. Pat. No. 3,496,661 of common assignment. It is this particular structure that the present invention improves.